Electrically conductive polymer compositions

ABSTRACT

The present invention relates to electrically conductive polymer compositions, and their use in organic electronic devices. The electrically conductive polymer compositions include (i) an intrinsically conductive polymer having at least one monomer unit which is a pyridine-fused heteroaromatic and (ii) a fluorinated acid polymer.

FIELD OF THE DISCLOSURE

This disclosure relates in general to electrically conductive polymercompositions, and their use in organic electronic devices.

BACKGROUND INFORMATION

Organic electronic devices define a category of products that include anactive layer. Such devices convert electrical energy into radiation,detect signals through electronic processes, convert radiation intoelectrical energy, or include one or more organic semiconductor layers.

Organic light-emitting diodes (OLEDs) are an organic electronic devicecomprising an organic layer capable of electroluminescence. OLEDscontaining conducting polymers can have the following configuration:

anode/buffer layer/EL material/cathode

The anode is typically any material that is transparent and has theability to inject holes into the EL material, such as, for example,indium/tin oxide (ITO). The anode is optionally supported on a glass orplastic substrate. EL materials include fluorescent compounds,fluorescent and phosphorescent metal complexes, conjugated polymers, andmixtures thereof. The cathode is typically any material (such as, e.g.,Ca or Ba) that has the ability to inject electrons into the EL material.

The buffer layer is typically an electrically conducting polymer andfacilitates the injection of holes from the anode into the EL materiallayer. Typical conducting polymers employed as buffer layers includepolyaniline and polydioxythiophenes such aspoly(3,4-ethylenedioxythiophene) (PEDT). These materials can be preparedby polymerizing aniline or dioxythiophene monomers in aqueous solutionin the presence of a water soluble polymeric acid, such aspoly(styrenesulfonic acid) (PSS), as described in, for example, U.S.Pat. No. 5,300,575.

The aqueous electrically conductive polymer dispersions synthesized withwater soluble polymeric sulfonic acids have undesirable low pH levels.The low pH can contribute to decreased stress life of an EL devicecontaining such a buffer layer, and contribute to corrosion within thedevice.

Electrically conducting polymers which have the ability to carry a highcurrent when subjected to a low electrical voltage, also have utility aselectrodes for electronic devices, such as thin film field effecttransistors. In such transistors, an organic semiconducting film whichhas high mobility for electron and/or hole charge carriers, is presentbetween source and drain electrodes. A gate electrode is on the oppositeside of the semiconducting polymer layer. To be useful for the electrodeapplication, the electrically conducting polymers and the liquids fordispersing or dissolving the electrically conducting polymers have to becompatible with the semiconducting polymers and the solvents for thesemiconducting polymers to avoid re-dissolution of either conductingpolymers or semiconducting polymers. Many conductive polymers haveconductivities which are too low for use as electrodes.

Thus, there is a continuing need for electrically conductive polymercompositions having improved physical and electrical properties.

SUMMARY OF THE DISCLOSURE

There is provided an electrically conductive polymer composition,comprising (i) an intrinsically conductive polymer having at least onemonomer unit comprising a pyridine-fused heteroaromatic, and (ii) afluorinated acid polymer.

In another embodiment, there is provided an aqueous dispersion of theabove conductive polymer and a fluorinated acid polymer.

In another emobodiment, there is provided a method for producing anelectrically conductive polymer composition, said method comprisingforming a combination of water, at least one precursor monomer having atleast one monomer unit comprising a pyridine-fused heteroaromatic, atleast one fluorinated acid polymer, an oxidizing agent, and a catalyst,in any order, provided that at least a portion of the fluorinated acidpolymer is present when the conductive monomers are added or when theoxidizing agent is added.

In another embodiment, electronic devices comprising at least one layercomprising the new conductive polymer composition are provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an organic electronic device.

The FIGURE(s) are provided by way of example and are not intended tolimit the invention.

The foregoing general description and the following detailed descriptionare exemplary and explanatory only and are not restrictive of theinvention, as defined in the appended claims.

DETAILED DESCRIPTION

In one embodiment, there is provided an electrically conductive polymercomposition, comprising an intrinsically conductive polymer and afluorinated acid polymer.

Many aspects and embodiments have been described above and are merelyexemplary and not limiting. After reading this specification, skilledartisans appreciate that other aspects and embodiments are possiblewithout departing from the scope of the invention.

Other features and benefits of any one or more of the embodiments willbe apparent from the following detailed description, and from theclaims. The detailed description first addresses Definitions andClarification of Terms followed by the Conductive Precursor Monomer, theNon-Conductive Precursor Monomer, the Fluorinated Acid Polymer, thePreparation of Conductive Compositions, Buffer Layers, ElectronicDevices, and finally Examples.

1. Definitions and Clarification of Terms

As used herein, the term “polymer” refers to a polymer or oligomerhaving at least 3 repeat units. The term includes homopolymers andcopolymers. The term “intrinsically conductive” refers to a materialwhich is capable of electrical conductivity without the addition ofcarbon black or conductive metal particles. In some embodiments, theintrinsically conductive polymer will form a film which has aconductivity of at least 10⁻⁶ S/cm. In some embodiments, theintrinsically conductive polymer is conductive in a protonated form andnot conductive in an unprotonated form.

The term “pyridine-fused heteroaromatic” refers to compound having apyridine ring fused to a 5-membered heteroaromatic ring. In someembodiments, the 5-membered heteroaromatic ring has a heteroatomselected from the group consisting of N, S, Se and Te.

The term “fluorinated acid polymer” refers to a polymer having groupswith acidic protons, and where at least one of the hydrogens bonded tocarbon in the polymer has been replaced by fluorine. The term “acidicgroup” refers to a group capable of ionizing to donate a hydrogen ion toa Brønsted base to form a salt.

The conductive polymers suitable for the new composition are made fromat least one monomer. Monomers which, when polymerized alone formhomopolymers which are intrinsically conductive, are referred to as“conductive precursor monomers.” Monomers which, when polymerized aloneform homopolymers which are not intrinsically conductive, are referredto as “non-conductive precursor monomers.” The conductive polymerssuitable for the new composition can be homopolymers or copolymers. Thecopolymers can be made from two or more conductive precursor monomers orfrom a combination of one or more conductive precursor monomers and oneor more non-conductive precursor monomers. The term “two or moremonomers” refers to two or more separate monomers that can bepolymerized together directly, and to two or more different monomersthat are reacted to form a single intermediate monomer, and thenpolymerized.

In one embodiment, the intrinsically conductive polymer is a copolymerof at least one first conductive precursor monomer which is apyridine-fused heteroaromatic, and at least one second conductiveprecursor monomer which is different from the first conductive precursormonomer. In one embodiment, the intrinsically conductive polymer isprepared by the oxidative polymerization of one or more conductiveprecursor monomers.

2. Conductive Precursor Monomers

The conductive polymer is made from at least one conductive precursormonomer having Formula I or Formula II below:

wherein:

R₁ through R₃ are independently selected so as to be the same ordifferent at each occurrence and are hydrogen or a substituent groupselected from the group consisting of alkyl, alkenyl, alkoxy, alkanoyl,alkylhio, aryloxy, alkylthioalkyl, alkylaryl, arylalkyl, amino,alkylamino, dialkylamino, aryl, alkylsulfinyl, alkoxyalkyl,alkylsulfonyl, arylthio, arylsulfinyl, alkoxycarbonyl, arylsulfonyl,acrylic acid, phosphoric acid, phosphonic acid, halogen, nitro, cyano,hydroxyl, epoxy, silane, siloxane, alcohol, benzyl, carboxylate, ether,ether carboxylate, amidosulfonate, ether sulfonate, ether sulfonic acid,ether sulfonimide, ester sulfonate, and urethane; or adjacent R groupstogether may form an alkylene or alkenylene chain completing a 3, 4, 5,6, or 7-membered aromatic or alicyclic ring, which ring may optionallyinclude one or more divalent nitrogen, sulfur, selenium, tellurium, oroxygen atoms, wherein any of the substituent groups may be fluorinated;

Q is NR′, S, Se or Te; and

R′ is selected from the group consisting of hydrogen, alkyl, alkenyl,aryl, alkanoyl, alkylthioalkyl, alkylaryl, arylalkyl, amino, epoxy,silane, siloxane, alcohol, benzyl, carboxylate, ether, ethercarboxylate, ether sulfonate, ester sulfonate, and urethane.

In some embodiments, one or more of the R groups is a fluorinated ethersulfonic acid or sulfonimide. In some embodiments, it is perfluorinated.In some embodiments, the R group is —O(CF₂)_(a)O(CF₂)_(b)R″, where a andb are the same or different and are an integer from 0-5, with theproviso that at least one of a and b is non-zero, and R″ is sulfonicacid or sulfonimide. In some embodiments, R has one of the structuresbelow:

As used herein, the term “alkyl” refers to a group derived from analiphatic hydrocarbon and includes linear, branched and cyclic groupswhich may be unsubstituted or substituted. The term “heteroalkyl” isintended to mean an alkyl group, wherein one or more of the carbon atomswithin the alkyl group has been replaced by another atom, such asnitrogen, oxygen, sulfur, and the like. The term “alkylene” refers to analkyl group having two points of attachment.

As used herein, the term “alkenyl” refers to a group derived from analiphatic hydrocarbon having at least one carbon-carbon double bond, andincludes linear, branched and cyclic groups which may be unsubstitutedor substituted. The term “heteroalkenyl” is intended to mean an alkenylgroup, wherein one or more of the carbon atoms within the alkenyl grouphas been replaced by another atom, such as nitrogen, oxygen, sulfur, andthe like. The term “alkenylene” refers to an alkenyl group having twopoints of attachment.

As used herein, the following terms for substituent groups refer to theformulae given below:

“alcohol” —R³—OH

“amido” —R³—C(O)N(R⁶)R⁶

“amidosulfonate” —R³—C(O)N(R⁶)R⁴—SO₃Z

“benzyl” —CH₂—C₆H₅

“carboxylate” —R³—C(O)O—Z or —R³—O—C(O)—Z

“ether” —R³—(O—R⁵)_(p)—O—R⁵

“ether carboxylate” —R³—O—R⁴—C(O)O—Z or —R³—O—R⁴—O—C(O)—Z

“ether sulfonate” —R³—O—R⁴—SO₃Z

“ester sulfonate” —R³—O—C(O)—R⁴—SO₃Z

“sulfonimide” —R³—SO₂—NH—SO₂—R⁵

“urethane” —R³—O—C(O)—N(R⁶)₂

where all “R” groups are the same or different at each occurrence and:

R³ is a single bond or an alkylene group

R⁴ is an alkylene group

R⁵ is an alkyl group

R⁶ is hydrogen or an alkyl group

p is 0 or an integer from 1 to 20

Z is H, alkali metal, alkaline earth metal, N(R⁵)₄ or R⁵

Any of the above groups may further be unsubstituted or substituted, andany group may have F substituted for one or more hydrogens, includingperfluorinated groups. In one embodiment, the alkyl and alkylene groupshave from 1-20 carbon atoms.

In some embodiments, the intrinsically conductive polymer is ahomopolymer of a monomer having Formula I or Formula II.

In some embodiments, the intrinsically conductive polymer is a copolymerof a first conductive precursor monomer having Formula I or Formula II,and at least one second conductive precursor monomer, which is differentfrom the first conductive precursor monomer. In some embodiments, thesecond conductive precursor monomer has Formula I or Formula II. In someembodiments, the first conductive precursor monomer has Formula I andthe second conductive precursor monomer has Formula II. In someembodiments, the second conductive precursor monomer is selected fromthe group consisting of thiophenes, selenophenes, tellurophenes,pyrroles, anilines, and polycyclic aromatics. The term “polycyclicaromatic” refers to compounds having more than one aromatic ring. Therings may be joined by one or more bonds, or they may be fused together.The term “aromatic ring” is intended to include heteroaromatic rings. A“polycyclic heteroaromatic” compound has at least one heteroaromaticring.

3. Non-Conductive Precursor Monomers

In one embodiment, the intrinsically conductive polymer is a copolymerof at least one conductive precursor monomer having Formula I or FormulaII, as described above, and at least one non-conductive precursormonomer. Any type of non-conductive precursor monomer can be used, solong as it does not detrimentally affect the desired properties of thecopolymer. In one embodiment, the non-conductive precursor monomercomprises no more than 50%, based on the total number of monomer units.In one embodiment, the non-conductive precursor monomer comprises nomore than 30%, based on the total number of monomer units. In oneembodiment, the non-conductive precursor monomer comprises no more than10%, based on the total number of monomer units.

Exemplary types non-conductive precursor monomers include, but are notlimited to, alkenyl, alkynyl, arylene, and heteroarylene. Examples ofnon-conductive monomers include, but are not limited to, fluorene,oxadiazole, thiadiazole, benzothiadiazole, phenylenevinylene,phenyleneethynylene, pyridine, diazines, and triazines, all of which maybe further substituted.

In one embodiment, the copolymers are made by first forming anintermediate precursor monomer having the structure A-B-C, where A and Crepresent conductive precursor monomers, which can be the same ordifferent, and B represents a non-conductive precursor monomer. TheA-B-C intermediate precursor monomer can be prepared using standardsynthetic organic techniques, such as Yamamoto, Stille, Grignardmetathesis, Suzuki, and Negishi couplings. The copolymer is then formedby oxidative polymerization of the intermediate precursor monomer alone,or with one or more additional conductive precursor monomers.

4. Fluorinated Acid Polymer

The fluorinated acid polymer can be any polymer which is fluorinated andhas groups with acidic protons. As used herein, the term “fluorinated”means that at least one hydrogen bonded to a carbon has been replacedwith a fluorine. The term includes partially and fully fluorinatedmaterials. In one embodiment, the fluorinated acid polymer is highlyfluorinated. The term “highly fluorinated” means that at least 50% ofthe available hydrogens bonded to a carbon, have been replaced withfluorine. The group having an acidic proton, is hereinafter referred toas an “acidic group.” In one embodiment, the acidic group has a pKa ofless than 3. In one embodiment, the acidic group has a pKa of less than0. In one embodiment, the acidic group has a pKa of less than −5. Theacidic group can be attached directly to the polymer backbone, or it canbe attached to side chains on the polymer backbone. Examples of acidicgroups include, but are not limited to, carboxylic acid groups, sulfonicacid groups, sulfonimide groups, phosphoric acid groups, phosphonic acidgroups, and combinations thereof. The acidic groups can all be the same,or the polymer may have more than one type of acidic group.

In one embodiment, the fluorinated acid polymer is water-soluble. In oneembodiment, the fluorinated acid polymer is dispersible in water.

In one embodiment, the fluorinated acid polymer is organic solventwettable. The term “organic solvent wettable” refers to a materialwhich, when formed into a film, is wettable by organic solvents. Theterm also includes polymeric acids which are not film-forming alone, butwhich form an electrically conductive polymer composition which iswettable. In one embodiment, wettable materials form films which arewettable by phenylhexane with a contact angle no greater than 40°. Themethods for measuring contact angles are well known.

In one embodiment, the polymer backbone is fluorinated. Examples ofsuitable polymeric backbones include, but are not limited to,polyolefins, polyacrylates, polymethacrylates, polyimides, polyamides,polyaramids, polyacrylamides, polystyrenes, and copolymers thereof. Inone embodiment, the polymer backbone is highly fluorinated. In oneembodiment, the polymer backbone is fully fluorinated.

In one embodiment, the acidic groups are selected from sulfonic acidgroups and sulfonimide groups. A sulfonimide group has the formula:

—SO₂—NH—SO₂—R

where R is an alkyl group.

In one embodiment, the acidic groups are on a fluorinated side chain. Inone embodiment, the fluorinated side chains are selected from alkylgroups, alkoxy groups, amido groups, ether groups, and combinationsthereof.

In one embodiment, the fluorinated acid polymer has a fluorinated olefinbackbone, with pendant fluorinated ether sulfonate, fluorinated estersulfonate, or fluorinated ether sulfonimide groups. In one embodiment,the polymer is a copolymer of 1,1-difluoroethylene and2-(1,1-difluoro-2-(trifluoromethyl)allyloxy)-1,1,2,2-tetrafluoroethanesulfonicacid. In one embodiment, the polymer is a copolymer of ethylene and2-(2-(1,2,2-trifluorovinyloxy)-1,1,2,3,3,3-hexafluoropropoxy)-1,1,2,2-tetrafluoroethanesulfonicacid. These copolymers can be made as the corresponding sulfonylfluoride polymer and then can be converted to the sulfonic acid form.

In one embodiment, the fluorinated acid polymer is homopolymer orcopolymer of a fluorinated and partially sulfonated poly(arylene ethersulfone). The copolymer can be a block copolymer. Examples of comonomersinclude, but are not limited to butadiene, butylene, isobutylene,styrene, and combinations thereof.

In one embodiment, the fluorinated acid polymer is a homopolymer orcopolymer of monomers having Formula VII:

where:

b is an integer from 1 to 5,

R¹³ is OH or NHR¹⁴, and

R¹⁴ is alkyl, fluoroalkyl, sulfonylalkyl, or sulfonylfluoroalkyl.In one embodiment, the monomer is “SFS” or SFSI″ shown below:

After polymerization, the polymer can be converted to the acid form.

In one embodiment, the fluorinated acid polymer is a homopolymer orcopolymer of a trifluorostyrene having acidic groups. In one embodiment,the trifluorostyrene monomer has Formula VIII:

where:

W is selected from (CF₂)_(b), O(CF₂)_(b), S(CF₂)_(b),(CF₂)_(b)O(CF₂)_(b),

b is independently an integer from 1 to 5,

R¹³ is OH or NHR¹⁴, and

R¹⁴ is alkyl, fluoroalkyl, sulfonylalkyl, or sulfonylfluoroalkyl.

In one embodiment, the fluorinated acid polymer is a sulfonimide polymerhaving Formula IX:

where:

R_(f) is selected from fluorinated alkylene, fluorinated heteroalkylene,fluorinated arylene, and fluorinated heteroarylene; and

n is at least 4.

In one embodiment of Formula IX, R_(f) is a perfluoroalkyl group. In oneembodiment, R_(f) is a perfluorobutyl group. In one embodiment, R_(f)contains ether oxygens. In one embodiment n is greater than 10.

In one embodiment, the fluorinated acid polymer comprises a fluorinatedpolymer backbone and a side chain having Formula X:

where:

R¹⁵ is a fluorinated alkylene group or a fluorinated heteroalkylenegroup;

R¹⁶ is a fluorinated alkyl or a fluorinated aryl group; and

a is 0 or an integer from 1 to 4.

In one embodiment, the fluorinated acid polymer has Formula XI:

where:

R¹⁶ is a fluorinated alkyl or a fluorinated aryl group;

c is independently 0 or an integer from 1 to 3; and

n is at least 4.

The synthesis of fluorinated acid polymers has been described in, forexample, A. Feiring et al., J. Fluorine Chemistry 2000, 105, 129-135; A.Feiring et al., Macromolecules 2000, 33, 9262-9271; D. D. Desmarteau, J.Fluorine Chem. 1995, 72, 203-208; A. J. Appleby et al., J. Electrochem.Soc. 1993, 140(1), 109-111; and Desmarteau, U.S. Pat. No. 5,463,005.

In one embodiment, the fluorinated acid polymer comprises at least onerepeat unit derived from an ethylenically unsaturated compound havingthe structure (XII):

-   -   wherein d is 0, 1, or 2;    -   R¹⁷ to R²⁰ are independently H, halogen, alkyl or alkoxy of 1 to        10 carbon atoms, Y, C(R_(f)′)(R_(f)′)OR²¹, R⁴Y or OR⁴Y;    -   Y is COE², SO₂ E², or sulfonimide;    -   R²¹ is hydrogen or an acid-labile protecting group;    -   R_(f)′ is the same or different at each occurrence and is a        fluoroalkyl group of 1 to 10 carbon atoms, or taken together are        (CF₂)_(e)        -   where e is 2 to 10;    -   R⁴ is an alkylene group;    -   E² is OH, halogen, or OR⁵; and    -   R⁵ is an alkyl group;    -   with the proviso that at least one of R¹⁷ to R²⁰ is Y, R⁴Y or        OR⁴Y.    -   R⁴, R⁵, and R¹⁷ to R²⁰ may optionally be substituted by halogen        or ether oxygen.

Some illustrative, but nonlimiting, examples of representative monomersof structure (XII) are presented below:

wherein R²¹ is a group capable of forming or rearranging to a tertiarycation, more typically an alkyl group of 1 to 20 carbon atoms, and mosttypically t-butyl.

Compounds of structure (XII) wherein d=0, structure (XII-a), may beprepared by the cycloaddition reaction of unsaturated compounds ofstructure (XIII) with quadricyclane(tetracyclo[2.2.1.0^(2,6)0^(3,5)]heptane) as shown in the equationbelow.

The reaction may be conducted at temperatures ranging from about 0° C.to about 200° C., more typically from about 30° C. to about 150° C. inthe absence or presence of an inert solvent such as diethyl ether. Forreactions conducted at or above the boiling point of one or more of thereagents or solvent, a closed reactor is typically used to avoid loss ofvolatile components. Compounds of structure (XII) with higher values ofd (i.e., d=1 or 2) may be prepared by reaction of compounds of structure(XII) with d=0 with cyclopentadiene, as is known in the art.

In one embodiment, the fluorinated acid polymer also comprises a repeatunit derived from at least one ethylenically unsaturated compoundcontaining at least one fluorine atom attached to an ethylenicallyunsaturated carbon. The fluoroolefin comprises 2 to 20 carbon atoms.Representative fluoroolefins include, but are not limited to,tetrafluoroethylene, hexafluoropropylene, chlorotrifluoroethylene,vinylidene fluoride, vinyl fluoride,perfluoro-(2,2-dimethyl-1,3-dioxole),perfluoro-(2-methylene-4-methyl-1,3-dioxolane), CF₂═CFO(CF₂)_(t)CF═CF₂,where t is 1 or 2, and R_(f)″OCF═CF₂ wherein R_(f)″ is a saturatedfluoroalkyl group of from 1 to about ten carbon atoms. In oneembodiment, the comonomer is tetrafluoroethylene.

In one embodiment, the fluorinated acid polymer comprises a polymericbackbone having pendant groups comprising siloxane sulfonic acid. In oneembodiment, the siloxane pendant groups have the formula below:

—O_(a)Si(OH)_(b-a)R²² _(3-b)R²³R_(f)SO₃H

wherein:

a is from 1 to b;

b is from 1 to 3;

R²² is a non-hydrolyzable group independently selected from the groupconsisting of alkyl, aryl, and arylalkyl;

R²³ is a bidentate alkylene radical, which may be substituted by one ormore ether oxygen atoms, with the proviso that R²³ has at least twocarbon atoms linearly disposed between Si and R_(f); and

R_(f) is a perfluoralkylene radical, which may be substituted by one ormore ether oxygen atoms.

In one embodiment, the fluorinated acid polymer having pendant siloxanegroups has a fluorinated backbone. In one embodiment, the backbone isperfluorinated.

In one embodiment, the fluorinated acid polymer has a fluorinatedbackbone and pendant groups represented by the Formula (XIV)

—O_(g)—[CF(R_(f) ²)CF—O_(h)]_(i)—CF₂CF₂SO₃H  (XIV)

wherein R_(f) ² is F or a perfluoroalkyl radical having 1-10 carbonatoms either unsubstituted or substituted by one or more ether oxygenatoms, h=0 or 1, i=0 to 3, and g=0 or 1.

In one embodiment, the fluorinated acid polymer has formula (XV)

where j≧0, k≧0 and 4≦(j+k)≦199, Q¹ and Q² are F or H, R_(f) ² is F or aperfluoroalkyl radical having 1-10 carbon atoms either unsubstituted orsubstituted by one or more ether oxygen atoms, h=0 or 1, i=0 to 3, g=0or 1. In one embodiment R_(f) ² is —CF₃, g=1, h=1, and i=1. In oneembodiment the pendant group is present at a concentration of 3-10mol-%.

In one embodiment, Q¹ is H, k≧0, and Q² is F, which may be synthesizedaccording to the teachings of Connolly et al., U.S. Pat. No. 3,282,875.In another preferred embodiment, Q¹ is H, Q² is H, g=0, R_(f) ² is F,h=1, and i−1, which may be synthesized according to the teachings ofco-pending application Ser. No. 60/105,662. Still other embodiments maybe synthesized according to the various teachings in Drysdale et al., WO9831716(A1), and co-pending US applications Choi et al, WO 99/52954(A1),and 60/176,881.

In one embodiment, the fluorinated acid polymer is a colloid-formingpolymeric acid. As used herein, the term “colloid-forming” refers tomaterials which are insoluble in water, and form colloids when dispersedinto an aqueous medium. The colloid-forming polymeric acids typicallyhave a molecular weight in the range of about 10,000 to about 4,000,000.In one embodiment, the polymeric acids have a molecular weight of about100,000 to about 2,000,000. Colloid particle size typically ranges from2 nanometers (nm) to about 140 nm. In one embodiment, the colloids havea particle size of 2 nm to about 30 nm. Any colloid-forming polymericmaterial having acidic protons can be used. In one embodiment, thecolloid-forming fluorinated polymeric acid has acidic groups selectedfrom carboxylic groups, sulfonic acid groups, and sulfonimide groups. Inone embodiment, the colloid-forming fluorinated polymeric acid is apolymeric sulfonic acid. In one embodiment, the colloid-formingpolymeric sulfonic acid is perfluorinated. In one embodiment, thecolloid-forming polymeric sulfonic acid is a perfluoroalkylenesulfonicacid.

In one embodiment, the colloid-forming polymeric acid is ahighly-fluorinated sulfonic acid polymer (“FSA polymer”). “Highlyfluorinated” means that at least about 50% of the total number ofhalogen and hydrogen atoms in the polymer are fluorine atoms, an in oneembodiment at least about 75%, and in another embodiment at least about90%. In one embodiment, the polymer is perfluorinated. The term“sulfonate functional group” refers to either to sulfonic acid groups orsalts of sulfonic acid groups, and in one embodiment alkali metal orammonium salts. The functional group is represented by the formula—SO₃E⁵ where E⁵ is a cation, also known as a “counterion”. E⁵ may be H,Li, Na, K or N(R₁)(R₂)(R₃)(R₄), and R₁, R₂, R₃, and R₄ are the same ordifferent and are and in one embodiment H, CH₃ or C₂H₅. In anotherembodiment, E⁵ is H, in which case the polymer is said to be in the“acid form”. E⁵ may also be multivalent, as represented by such ions asCa++, and Al+++. It is clear to the skilled artisan that in the case ofmultivalent counterions, represented generally as M^(x+), the number ofsulfonate functional groups per counterion will be equal to the valence“x”.

In one embodiment, the FSA polymer comprises a polymer backbone withrecurring side chains attached to the backbone, the side chains carryingcation exchange groups. Polymers include homopolymers or copolymers oftwo or more monomers. Copolymers are typically formed from anonfunctional monomer and a second monomer carrying the cation exchangegroup or its precursor, e.g., a sulfonyl fluoride group (—SO₂F), whichcan be subsequently hydrolyzed to a sulfonate functional group. Forexample, copolymers of a first fluorinated vinyl monomer together with asecond fluorinated vinyl monomer having a sulfonyl fluoride group(—SO₂F) can be used. Possible first monomers include tetrafluoroethylene(TFE), hexafluoropropylene, vinyl fluoride, vinylidine fluoride,trifluoroethylene, chlorotrifluoroethylene, perfluoro(alkyl vinylether), and combinations thereof. TFE is a preferred first monomer.

In other embodiments, possible second monomers include fluorinated vinylethers with sulfonate functional groups or precursor groups which canprovide the desired side chain in the polymer. Additional monomers,including ethylene, propylene, and R—CH═CH₂ where R is a perfluorinatedalkyl group of 1 to 10 carbon atoms, can be incorporated into thesepolymers if desired. The polymers may be of the type referred to hereinas random copolymers, that is copolymers made by polymerization in whichthe relative concentrations of the comonomers are kept as constant aspossible, so that the distribution of the monomer units along thepolymer chain is in accordance with their relative concentrations andrelative reactivities. Less random copolymers, made by varying relativeconcentrations of monomers in the course of the polymerization, may alsobe used. Polymers of the type called block copolymers, such as thatdisclosed in European Patent Application No. 1 026 152 A1, may also beused.

In one embodiment, FSA polymers include a highly fluorinated, and in oneembodiment perfluorinated, carbon backbone and side chains representedby the formula

—(O—CF₂CFR_(f) ³)_(a)—O—CF₂CFR_(f) ⁴SO₃E⁵

wherein R_(f) ³ and R_(f) ⁴ are independently selected from F, Cl or aperfluorinated alkyl group having 1 to 10 carbon atoms, a=0, 1 or 2, andE⁵ is H, Li, Na, K or N(R1)(R2)(R3)(R4) and R1, R2, R3, and R4 are thesame or different and are and in one embodiment H, CH₃ or C₂H₅. Inanother embodiment E⁵ is H. As stated above, E⁵ may also be multivalent.

In one embodiment, the FSA polymers include, for example, polymersdisclosed in U.S. Pat. No. 3,282,875 and in U.S. Pat. Nos. 4,358,545 and4,940,525. An example of preferred FSA polymer comprises aperfluorocarbon backbone and the side chain represented by the formula

—O—CF₂CF(CF₃)—O—CF₂CF₂SO₃E⁵

where X is as defined above. FSA polymers of this type are disclosed inU.S. Pat. No. 3,282,875 and can be made by copolymerization oftetrafluoroethylene (TFE) and the perfluorinated vinyl etherCF₂═CF—O—CF₂CF(CF₃)—O—CF₂CF₂SO₂F,perfluoro(3,6-dioxa-4-methyl-7-octenesulfonyl fluoride) (PDMOF),followed by conversion to sulfonate groups by hydrolysis of the sulfonylfluoride groups and ion exchanged as necessary to convert them to thedesired ionic form. An example of a polymer of the type disclosed inU.S. Pat. Nos. 4,358,545 and 4,940,525 has the side chain—O—CF₂CF₂SO₃E⁵, wherein E⁵ is as defined above. This polymer can be madeby copolymerization of tetrafluoroethylene (TFE) and the perfluorinatedvinyl ether CF₂═CF-β-CF₂CF₂SO₂F, perfluoro(3-oxa-4-pentenesulfonylfluoride) (POPF), followed by hydrolysis and further ion exchange asnecessary.

In one embodiment, the FSA polymers have an ion exchange ratio of lessthan about 33. In this application, “ion exchange ratio” or “IXR” isdefined as number of carbon atoms in the polymer backbone in relation tothe cation exchange groups. Within the range of less than about 33, IXRcan be varied as desired for the particular application. In oneembodiment, the IXR is about 3 to about 33, and in another embodimentabout 8 to about 23.

The cation exchange capacity of a polymer is often expressed in terms ofequivalent weight (EW). For the purposes of this application, equivalentweight (EW) is defined to be the weight of the polymer in acid formrequired to neutralize one equivalent of sodium hydroxide. In the caseof a sulfonate polymer where the polymer has a perfluorocarbon backboneand the side chain is —O—CF₂—CF(CF₃)—O—CF₂—CF₂—SO₃H (or a salt thereof),the equivalent weight range which corresponds to an IXR of about 8 toabout 23 is about 750 EW to about 1500 EW. IXR for this polymer can berelated to equivalent weight using the formula: 50 IXR+344=EW. While thesame IXR range is used for sulfonate polymers disclosed in U.S. Pat.Nos. 4,358,545 and 4,940,525, e.g., the polymer having the side chain—O—CF₂CF₂SO₃H (or a salt thereof), the equivalent weight is somewhatlower because of the lower molecular weight of the monomer unitcontaining a cation exchange group. For the preferred IXR range of about8 to about 23, the corresponding equivalent weight range is about 575 EWto about 1325 EW. IXR for this polymer can be related to equivalentweight using the formula: 50 IXR+178=EW.

The FSA polymers can be prepared as colloidal aqueous dispersions. Theymay also be in the form of dispersions in other media, examples of whichinclude, but are not limited to, alcohol, water-soluble ethers, such astetrahydrofuran, mixtures of water-soluble ethers, and combinationsthereof. In making the dispersions, the polymer can be used in acidform. U.S. Pat. Nos. 4,433,082, 6,150,426 and WO 03/006537 disclosemethods for making of aqueous alcoholic dispersions. After thedispersion is made, concentration and the dispersing liquid compositioncan be adjusted by methods known in the art.

Aqueous dispersions of the colloid-forming polymeric acids, includingFSA polymers, typically have particle sizes as small as possible and anEW as small as possible, so long as a stable colloid is formed.

Aqueous dispersions of FSA polymer are available commericially asNafion® dispersions, from E. I. du Pont de Nemours and Company(Wilmington, Del.).

Some of the polymers described hereinabove may be formed in non-acidform, e.g., as salts, esters, or sulfonyl fluorides. They will beconverted to the acid form for the preparation of conductivecompositions, described below.

5. Preparation of Conductive Compositions

The new electrically conductive polymer composition is prepared by (i)polymerizing the precursor monomers in the presence of the fluorinatedacid polymer; or (ii) first forming the intrinsically conductive polymerand combining it with the fluorinated acid polymer.

(i) Polymerizing Precursor Monomers in the Presence of the FluorinatedAcid Polymer

In one embodiment, the electrically conductive polymer composition isformed by the oxidative polymerization of the precursor monomers in thepresence of the fluorinated acid polymer. In one embodiment, theprecursor monomers comprise one type of conductive precursor monomer. Inone embodiment, the precursor monomers comprise two or more differentconductive precursor monomers. In one embodiment, the monomers comprisean intermediate precursor monomer having the structure A-B-C, where Aand C represent conductive precursor monomers, which can be the same ordifferent, and B represents a non-conductive precursor monomer. In oneembodiment, the intermediate precursor monomer is polymerized with oneor more conductive precursor monomers.

In one embodiment, the oxidative polymerization is carried out in ahomogeneous aqueous solution. In another embodiment, the oxidativepolymerization is carried out in an emulsion of water and an organicsolvent. In general, some water is present in order to obtain adequatesolubility of the oxidizing agent and/or catalyst. Oxidizing agents suchas ammonium persulfate, sodium persulfate, potassium persulfate, and thelike, can be used. A catalyst, such as ferric chloride, or ferricsulfate may also be present. The resulting polymerized product will be asolution, dispersion, or emulsion of the conductive polymer inassociation with the fluorinated acid polymer. In one embodiment, theintrinsically conductive polymer is positively charged, and the chargesare balanced by the fluorinated acid polymer anion.

In one embodiment, the method of making an aqueous dispersion of the newconductive polymer composition includes forming a reaction mixture bycombining water, at least two precursor monomers, at least onefluorinated acid polymer, and an oxidizing agent, in any order, providedthat at least a portion of the fluorinated acid polymer is present whenat least one of the precursor monomersand the oxidizing agent is added.

In one embodiment, the method of making the new conductive polymercomposition comprises:

(a) providing an aqueous solution or dispersion of a fluorinated acidpolymer;

(b) adding an oxidizer to the solutions or dispersion of step (a); and

(c) adding at least one precursor monomer to the mixture of step (b).

In another embodiment, the precursor monomer is added to the aqueoussolution or dispersion of the fluorinated acid polymer prior to addingthe oxidizer. Step (b) above, which is adding oxidizing agent, is thencarried out.

In another embodiment, a mixture of water and the precursor monomer isformed, in a concentration typically in the range of about 0.5% byweight to about 4.0% by weight total precursor monomer. This precursormonomer mixture is added to the aqueous solution or dispersion of thefluorinated acid polymer, and steps (b) above which is adding oxidizingagent is carried out.

In another embodiment, the aqueous polymerization mixture may include apolymerization catalyst, such as ferric sulfate, ferric chloride, andthe like. The catalyst is added before the last step. In anotherembodiment, a catalyst is added together with an oxidizing agent.

In one embodiment, the polymerization is carried out in the presence ofco-dispersing liquids which are miscible with water. Examples ofsuitable co-dispersing liquids include, but are not limited to ethers,alcohols, alcohol ethers, cyclic ethers, ketones, nitriles, sulfoxides,amides, and combinations thereof. In one embodiment, the co-dispersingliquid is an alcohol. In one embodiment, the co-dispersing liquid is anorganic solvent selected from n-propanol, isopropanol, t-butanol,dimethylacetamide, dimethylformamide, N-methylpyrrolidone, and mixturesthereof. In general, the amount of co-dispersing liquid should be lessthan about 60% by volume. In one embodiment, the amount of co-dispersingliquid is less than about 30% by volume. In one embodiment, the amountof co-dispersing liquid is between 5 and 50% by volume. The use of aco-dispersing liquid in the polymerization significantly reducesparticle size and improves filterability of the dispersions. Inaddition, buffer materials obtained by this process show an increasedviscosity and films prepared from these dispersions are of high quality.

The co-dispersing liquid can be added to the reaction mixture at anypoint in the process.

In one embodiment, the polymerization is carried out in the presence ofa co-acid which is a Brønsted acid. The acid can be an inorganic acid,such as HCl, sulfuric acid, and the like, or an organic acid, such asacetic acid or p-toluenesulfonic acid. Alternatively, the acid can be awater soluble polymeric acid such as poly(styrenesulfonic acid),poly(2-acrylamido-2-methyl-1-propanesulfonic acid, or the like, or asecond fluorinated acid polymer, as described above. Combinations ofacids can be used.

The co-acid can be added to the reaction mixture at any point in theprocess prior to the addition of either the oxidizer or the precursormonomer, whichever is added last. In one embodiment, the co-acid isadded before both the precursor monomers and the fluorinated acidpolymer, and the oxidizer is added last. In one embodiment the co-acidis added prior to the addition of the precursor monomers, followed bythe addition of the fluorinated acid polymer, and the oxidizer is addedlast.

In one embodiment, the polymerization is carried out in the presence ofboth a co-dispersing liquid and a co-acid.

In one embodiment, a reaction vessel is charged first with a mixture ofwater, alcohol co-dispersing agent, and inorganic co-acid. To this isadded, in order, the precursor monomers, an aqueous solution ordispersion of fluorinated acid polymer, and an oxidizer. The oxidizer isadded slowly and dropwise to prevent the formation of localized areas ofhigh ion concentration which can destabilize the mixture. In anotherembodiment, the oxidizer and precursor monomers are injected into thereaction mixture separately and simultaneously at a controlled rate. Themixture is stirred and the reaction is then allowed to proceed at acontrolled temperature. When polymerization is completed, the reactionmixture is treated with a strong acid cation resin, stirred andfiltered; and then treated with a base anion exchange resin, stirred andfiltered. Alternative orders of addition can be used, as discussedabove.

In the method of making the new conductive polymer composition, themolar ratio of oxidizer to total precursor monomer is generally in therange of 0.1 to 2.0; and in one embodiment is 0.4 to 1.5. The molarratio of fluorinated acid polymer to total precursor monomer isgenerally in the range of 0.2 to 5. In one embodiment, the ratio is inthe range of 1 to 4. The overall solid content is generally in the rangeof about 1.0% to 10% in weight percentage; and in one embodiment ofabout 2% to 4.5%. The reaction temperature is generally in the range ofabout 4° C. to 50° C.; in one embodiment about 20° C. to 35° C. Themolar ratio of optional co-acid to precursor monomer is about 0.05 to 4.The addition time of the oxidizer influences particle size andviscosity. Thus, the particle size can be reduced by slowing down theaddition speed. In parallel, the viscosity is increased by slowing downthe addition speed. The reaction time is generally in the range of about1 to about 30 hours.

(ii) Combining Intrinsically Conductive Polymers with Fluorinated AcidPolymers

In one embodiment, the intrinsically conductive polymers are formedseparately from the fluorinated acid polymer. In one embodiment, thepolymers are prepared by oxidatively polymerizing the correspondingmonomers in aqueous solution. In one embodiment, the oxidativepolymerization is carried out in the presence of a water soluble acid.In one embodiment, the acid is a water-soluble non-fluororinatedpolymeric acid. In one embodiment, the acid is a non-fluorinatedpolymeric sulfonic acid. Some non-limiting examples of the acids arepoly(styrenesulfonic acid) (“PSSA”),poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (“PAAMPSA”), andmixtures thereof. The acid anion provides the counterion for thepositive charge on the conductive polymer. The oxidative polymerizationis carried out using an oxidizing agent such as ammonium persulfate,sodium persulfate, and mixtures thereof.

The new electrically conductive polymer composition is prepared byblending the intrinsically conductive polymer with the fluorinated acidpolymer. This can be accomplished by adding an aqueous dispersion of theintrinsically conductive polymer to a dispersion or solution of thepolymeric acid. In one embodiment, the composition is further treatedusing sonication or microfluidization to ensure mixing of thecomponents.

In one embodiment, one or both of the intrinsically conductive polymerand fluorinated acid polymer are isolated in solid form. The solidmaterial can be redispersed in water or in an aqueous solution ordispersion of the other component. For example, intrinsically conductivepolymer solids can be dispersed in an aqueous solution or dispersion ofa fluorinated acid polymer.

(iii) pH Adjustment

As synthesized, the aqueous dispersions of the new conductive polymercomposition generally have a very low pH. In one embodiment, the pH isadjusted to higher values, without adversely affecting the properties indevices. In one embodiment, the pH of the dispersion is adjusted toabout 1.5 to about 4. In one embodiment, the pH is adjusted to between 3and 4. It has been found that the pH can be adjusted using knowntechniques, for example, ion exchange or by titration with an aqueousbasic solution.

In one embodiment, after completion of the polymerization reaction, theas-synthesized aqueous dispersion is contacted with at least one ionexchange resin under conditions suitable to remove decomposed species,side reaction products, and unreacted monomers, and to adjust pH, thusproducing a stable, aqueous dispersion with a desired pH. In oneembodiment, the as-synthesized aqueous dispersion is contacted with afirst ion exchange resin and a second ion exchange resin, in any order.The as-synthesized aqueous dispersion can be treated with both the firstand second ion exchange resins simultaneously, or it can be treatedsequentially with one and then the other.

Ion exchange is a reversible chemical reaction wherein an ion in a fluidmedium (such as an aqueous dispersion) is exchanged for a similarlycharged ion attached to an immobile solid particle that is insoluble inthe fluid medium. The term “ion exchange resin” is used herein to referto all such substances. The resin is rendered insoluble due to thecrosslinked nature of the polymeric support to which the ion exchanginggroups are attached. Ion exchange resins are classified as cationexchangers or anion exchangers. Cation exchangers have positivelycharged mobile ions available for exchange, typically protons or metalions such as sodium ions. Anion exchangers have exchangeable ions whichare negatively charged, typically hydroxide ions.

In one embodiment, the first ion exchange resin is a cation, acidexchange resin which can be in protonic or metal ion, typically sodiumion, form. The second ion exchange resin is a basic, anion exchangeresin. Both acidic, cation including proton exchange resins and basic,anion exchange resins are contemplated for use in the practice of theinvention. In one embodiment, the acidic, cation exchange resin is aninorganic acid, cation exchange resin, such as a sulfonic acid cationexchange resin. Sulfonic acid cation exchange resins contemplated foruse in the practice of the invention include, for example, sulfonatedstyrene-divinylbenzene copolymers, sulfonated crosslinked styrenepolymers, phenol-formaldehyde-sulfonic acid resins,benzene-formaldehyde-sulfonic acid resins, and mixtures thereof. Inanother embodiment, the acidic, cation exchange resin is an organicacid, cation exchange resin, such as carboxylic acid, acrylic orphosphorous cation exchange resin. In addition, mixtures of differentcation exchange resins can be used.

In another embodiment, the basic, anionic exchange resin is a tertiaryamine anion exchange resin. Tertiary amine anion exchange resinscontemplated for use in the practice of the invention include, forexample, tertiary-aminated styrene-divinylbenzene copolymers,tertiary-aminated crosslinked styrene polymers, tertiary-aminatedphenol-formaldehyde resins, tertiary-aminated benzene-formaldehyderesins, and mixtures thereof. In a further embodiment, the basic,anionic exchange resin is a quaternary amine anion exchange resin, ormixtures of these and other exchange resins.

The first and second ion exchange resins may contact the as-synthesizedaqueous dispersion either simultaneously, or consecutively. For example,in one embodiment both resins are added simultaneously to anas-synthesized aqueous dispersion of an electrically conducting polymer,and allowed to remain in contact with the dispersion for at least about1 hour, e.g., about 2 hours to about 20 hours. The ion exchange resinscan then be removed from the dispersion by filtration. The size of thefilter is chosen so that the relatively large ion exchange resinparticles will be removed while the smaller dispersion particles willpass through. Without wishing to be bound by theory, it is believed thatthe ion exchange resins quench polymerization and effectively removeionic and non-ionic impurities and most of unreacted monomer from theas-synthesized aqueous dispersion. Moreover, the basic, anion exchangeand/or acidic, cation exchange resins renders the acidic sites morebasic, resulting in increased pH of the dispersion. In general, aboutone to five grams of ion exchange resin is used per gram of newconductive polymer composition.

In many cases, the basic ion exchange resin can be used to adjust the pHto the desired level. In some cases, the pH can be further adjusted withan aqueous basic solution such as a solution of sodium hydroxide,ammonium hydroxide, tetra-methylammonium hydroxide, or the like.

In another embodiment, more conductive dispersions are formed by theaddition of highly conductive additives to the aqueous dispersions ofthe new conductive polymer composition. Because dispersions withrelatively high pH can be formed, the conductive additives, especiallymetal additives, are not attacked by the acid in the dispersion.Examples of suitable conductive additives include, but are not limitedto metal particles and nanoparticles, nanowires, carbon nanotubes,graphite fibers or particles, carbon particles, and combinationsthereof.

6. Buffer Layers

In another embodiment of the invention, there are provided buffer layersdeposited from aqueous dispersions comprising the new conductive polymercomposition. The term “buffer layer” or “buffer material” is intended tomean electrically conductive or semiconductive materials and may haveone or more functions in an organic electronic device, including but notlimited to, planarization of the underlying layer, charge transportand/or charge injection properties, scavenging of impurities such asoxygen or metal ions, and other aspects to facilitate or to improve theperformance of the organic electronic device. The term “layer” is usedinterchangeably with the term “film” and refers to a coating covering adesired area. The term is not limited by size. The area can be as largeas an entire device or as small as a specific functional area such asthe actual visual display, or as small as a single sub-pixel. Layers andfilms can be formed by any conventional deposition technique, includingvapor deposition, liquid deposition (continuous and discontinuoustechniques), and thermal transfer. Continuous deposition techniques,inlcude but are not limited to, spin coating, gravure coating, curtaincoating, dip coating, slot-die coating, spray coating, and continuousnozzle coating. Discontinuous deposition techniques include, but are notlimited to, ink jet printing, gravure printing, and screen printing.

The dried films of the new conductive polymer composition are generallynot redispersible in water. Thus the buffer layer can be applied asmultiple thin layers. In addition, the buffer layer can be overcoatedwith a layer of different water-soluble or water-dispersible materialwithout being damaged. Buffer layers comprising the new conductivepolymer composition have been surprisingly found to have improvedwetability.

In another embodiment, there are provided buffer layers deposited fromaqueous dispersions comprising the new conductive polymer compositionblended with other water soluble or dispersible materials. Examples oftypes of materials which can be added include, but are not limited topolymers, dyes, coating aids, organic and inorganic conductive inks andpastes, charge transport materials, crosslinking agents, andcombinations thereof. The other water soluble or dispersible materialscan be simple molecules or polymers. Examples of suitable polymersinclude, but are not limited to, conductive polymers such aspolythiophenes, polyanilines, polypyrroles, polyacetylenes,poly(thienothiophenes), and combinations thereof.

7. Electronic Devices

In another embodiment of the invention, there are provided electronicdevices comprising at least one electroactive layer positioned betweentwo electrical contact layers, wherein the device further includes thenew buffer layer. The term “electroactive” when referring to a layer ormaterial is intended to mean a layer or material that exhibitselectronic or electro-radiative properties. An electroactive layermaterial may emit radiation or exhibit a change in concentration ofelectron-hole pairs when receiving radiation.

As shown in FIG. 1, a typical device, 100, has an anode layer 110, abuffer layer 120, an electroactive layer 130, and a cathode layer 150.Adjacent to the cathode layer 150 is an optionalelectron-injection/transport layer 140.

The device may include a support or substrate (not shown) that can beadjacent to the anode layer 110 or the cathode layer 150. Mostfrequently, the support is adjacent the anode layer 110. The support canbe flexible or rigid, organic or inorganic. Examples of supportmaterials include, but are not limited to, glass, ceramic, metal, andplastic films.

The anode layer 110 is an electrode that is more efficient for injectingholes compared to the cathode layer 150. The anode can include materialscontaining a metal, mixed metal, alloy, metal oxide or mixed oxide.Suitable materials include the mixed oxides of the Group 2 elements(i.e., Be, Mg, Ca, Sr, Ba, Ra), the Group 11 elements, the elements inGroups 4, 5, and 6, and the Group 8-10 transition elements. If the anodelayer 110 is to be light transmitting, mixed oxides of Groups 12, 13 and14 elements, such as indium-tin-oxide, may be used. As used herein, thephrase “mixed oxide” refers to oxides having two or more differentcations selected from the Group 2 elements or the Groups 12, 13, or 14elements. Some non-limiting, specific examples of materials for anodelayer 110 include, but are not limited to, indium-tin-oxide (“ITO”),indium-zinc-oxide, aluminum-tin-oxide, gold, silver, copper, and nickel.The anode may also comprise an organic material, especially a conductingpolymer such as polyaniline, including exemplary materials as describedin “Flexible light-emitting diodes made from soluble conductingpolymer,” Nature vol. 357, pp 477 479 (11 Jun. 1992). At least one ofthe anode and cathode should be at least partially transparent to allowthe generated light to be observed.

The anode layer 110 may be formed by a chemical or physical vapordeposition process or spin-cast process. Chemical vapor deposition maybe performed as a plasma-enhanced chemical vapor deposition (“PECVD”) ormetal organic chemical vapor deposition (“MOCVD”). Physical vapordeposition can include all forms of sputtering, including ion beamsputtering, as well as e-beam evaporation and resistance evaporation.Specific forms of physical vapor deposition include rf magnetronsputtering and inductively-coupled plasma physical vapor deposition(“IMP-PVD”). These deposition techniques are well known within thesemiconductor fabrication arts.

In one embodiment, the anode layer 110 is patterned during alithographic operation. The pattern may vary as desired. The layers canbe formed in a pattern by, for example, positioning a patterned mask orresist on the first flexible composite barrier structure prior toapplying the first electrical contact layer material. Alternatively, thelayers can be applied as an overall layer (also called blanket deposit)and subsequently patterned using, for example, a patterned resist layerand wet chemical or dry etching techniques. Other processes forpatterning that are well known in the art can also be used.

The buffer layer 120 is usually deposited onto substrates using avariety of techniques well-known to those skilled in the art. Typicaldeposition techniques, as discussed above, include vapor deposition,liquid deposition (continuous and discontinuous techniques), and thermaltransfer.

An optional layer, not shown, may be present between the buffer layer120 and the electroactive layer 130. This layer may comprise holetransport materials. Examples of hole transport materials have beensummarized for example, in Kirk-Othmer Encyclopedia of ChemicalTechnology, Fourth Edition, Vol. 18, p. 837-860, 1996, by Y. Wang. Bothhole transporting molecules and polymers can be used. Commonly used holetransporting molecules include, but are not limited to:4,4′,4″-tris(N,N-diphenyl-amino)-triphenylamine (TDATA);4,4′,4″-tris(N-3-methylphenyl-N-phenyl-amino)-triphenylamine (MTDATA);N,N¹-diphenyl-N,N′-bis(3-methylphenyl)-[1, 1-biphenyl]-4,4′-diamine(TPD); 1,1-bis[(di-4-tolylamino) phenyl]cyclohexane (TAPC);N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(ETPD); tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine (PDA);α-phenyl-4-N,N-diphenylaminostyrene (TPS); p-(diethylamino)benzaldehydediphenylhydrazone (DEH); triphenylamine (TPA);bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane (MPMP);1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline(PPR or DEASP); 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane (DCZB);N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TTB);N,N′-bis(naphthalen-1-yl)-N,N′-bis-(phenyl)benzidine (α-NPB); andporphyrinic compounds, such as copper phthalocyanine. Commonly used holetransporting polymers include, but are not limited to,polyvinylcarbazole, (phenylmethyl)polysilane, poly(dioxythiophenes),polyanilines, and polypyrroles. It is also possible to obtain holetransporting polymers by doping hole transporting molecules such asthose mentioned above into polymers such as polystyrene andpolycarbonate.

Depending upon the application of the device, the electroactive layer130 can be a light-emitting layer that is activated by an appliedvoltage (such as in a light-emitting diode or light-emittingelectrochemical cell), a layer of material that responds to radiantenergy and generates a signal with or without an applied bias voltage(such as in a photodetector). In one embodiment, the electroactivematerial is an organic electroluminescent (“EL”) material, Any ELmaterial can be used in the devices, including, but not limited to,small molecule organic fluorescent compounds, fluorescent andphosphorescent metal complexes, conjugated polymers, and mixturesthereof. Examples of fluorescent compounds include, but are not limitedto, pyrene, perylene, rubrene, coumarin, derivatives thereof, andmixtures thereof. Examples of metal complexes include, but are notlimited to, metal chelated oxinoid compounds, such astris(8-hydroxyquinolato)aluminum (Alq3); cyclometalated iridium andplatinum electroluminescent compounds, such as complexes of iridium withphenylpyridine, phenylquinoline, or phenylpyrimidine ligands asdisclosed in Petrov et al., U.S. Pat. No. 6,670,645 and Published PCTApplications WO 03/063555 and WO 2004/016710, and organometalliccomplexes described in, for example, Published PCT Applications WO03/008424, WO 03/091688, and WO 03/040257, and mixtures thereof.Electroluminescent emissive layers comprising a charge carrying hostmaterial and a metal complex have been described by Thompson et al., inU.S. Pat. No. 6,303,238, and by Burrows and Thompson in published PCTapplications WO 00/70655 and WO 01/41512. Examples of conjugatedpolymers include, but are not limited to poly(phenylenevinylenes),polyfluorenes, poly(spirobifluorenes), polythiophenes,poly(p-phenylenes), copolymers thereof, and mixtures thereof.

Optional layer 140 can function both to facilitate electroninjection/transport, and can also serve as a confinement layer toprevent quenching reactions at layer interfaces. More specifically,layer 140 may promote electron mobility and reduce the likelihood of aquenching reaction if layers 130 and 150 would otherwise be in directcontact. Examples of materials for optional layer 140 include, but arenot limited to, metal chelated oxinoid compounds, such asbis(2-methyl-8-quinolinolato)(para-phenyl-phenolato)aluminum(III) (BAIQ)and tris(8-hydroxyquinolato)aluminum (Alq₃);tetrakis(8-hydroxyquinolinato)zirconium; azole compounds such as2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (PBD),3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (TAZ), and1,3,5-tri(phenyl-2-benzimidazole)benzene (TPBI); quinoxaline derivativessuch as 2,3-bis(4-fluorophenyl)quinoxaline; phenanthroline derivativessuch as 9,10-diphenylphenanthroline (DPA) and2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (DDPA); and any one ormore combinations thereof. Alternatively, optional layer 140 may beinorganic and comprise BaO, LiF, Li₂O, or the like.

The cathode layer 150 is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode layer 150can be any metal or nonmetal having a lower work function than the firstelectrical contact layer (in this case, the anode layer 110). As usedherein, the term “lower work function” is intended to mean a materialhaving a work function no greater than about 4.4 eV. As used herein,“higher work function” is intended to mean a material having a workfunction of at least approximately 4.4 eV.

Materials for the cathode layer can be selected from alkali metals ofGroup 1 (e.g., Li, Na, K, Rb, Cs), the Group 2 metals (e.g., Mg, Ca, Ba,or the like), the Group 12 metals, the lanthanides (e.g., Ce, Sm, Eu, orthe like), and the actinides (e.g., Th, U, or the like). Materials suchas aluminum, indium, yttrium, and combinations thereof, may also beused. Specific non-limiting examples of materials for the cathode layer150 include, but are not limited to, barium, lithium, cerium, cesium,europium, rubidium, yttrium, magnesium, samarium, and alloys andcombinations thereof.

The cathode layer 150 is usually formed by a chemical or physical vapordeposition process. In some embodiments, the cathode layer will bepatterned, as discussed above in reference to the anode layer 110.

Other layers in the device can be made of any materials which are knownto be useful in such layers upon consideration of the function to beserved by such layers.

In some embodiments, an encapsulation layer (not shown) is depositedover the contact layer 150 to prevent entry of undesirable components,such as water and oxygen, into the device 100. Such components can havea deleterious effect on the organic layer 130. In one embodiment, theencapsulation layer is a barrier layer or film. In one embodiment, theencapsulation layer is a glass lid.

Though not depicted, it is understood that the device 100 may compriseadditional layers. Other layers that are known in the art or otherwisemay be used. In addition, any of the above-described layers may comprisetwo or more sub-layers or may form a laminar structure. Alternatively,some or all of anode layer 110 the hole transport layer 120, theelectron transport layer 140, cathode layer 150, and other layers may betreated, especially surface treated, to increase charge carriertransport efficiency or other physical properties of the devices. Thechoice of materials for each of the component layers is preferablydetermined by balancing the goals of providing a device with high deviceefficiency with device operational lifetime considerations, fabricationtime and complexity factors and other considerations appreciated bypersons skilled in the art. It will be appreciated that determiningoptimal components, component configurations, and compositionalidentities would be routine to those of ordinary skill of in the art.

In one embodiment, the different layers have the following range ofthicknesses: anode 110, 500-5000 Å, in one embodiment 1000-2000 A;buffer layer 120, 50-2000 Å, in one embodiment 200-1000 Å; photoactivelayer 130, 10-2000 Å, in one embodiment 100-1000 Å; optional electrontransport layer 140, 50-2000 Å, in one embodiment 100-1000 Å; cathode150, 200-10000 Å, in one embodiment 300-5000 Å. The location of theelectron-hole recombination zone in the device, and thus the emissionspectrum of the device, can be affected by the relative thickness ofeach layer. Thus the thickness of the electron-transport layer should bechosen so that the electron-hole recombination zone is in thelight-emitting layer. The desired ratio of layer thicknesses will dependon the exact nature of the materials used.

In operation, a voltage from an appropriate power supply (not depicted)is applied to the device 100. Current therefore passes across the layersof the device 100. Electrons enter the organic polymer layer, releasingphotons. In some OLEDs, called active matrix OLED displays, individualdeposits of photoactive organic films may be independently excited bythe passage of current, leading to individual pixels of light emission.In some OLEDs, called passive matrix OLED displays, deposits ofphotoactive organic films may be excited by rows and columns ofelectrical contact layers.

As used herein, the terms “comprises,” “comprising,” “includes,”“including,” “has,” “having” or any other variation thereof, areintended to cover a non-exclusive inclusion. For example, a process,method, article, or apparatus that comprises a list of elements is notnecessarily limited to only those elements but may include otherelements not expressly listed or inherent to such process, method,article, or apparatus. Further, unless expressly stated to the contrary,“or” refers to an inclusive or and not to an exclusive or. For example,a condition A or B is satisfied by any one of the following: A is true(or present) and B is false (or not present), A is false (or notpresent) and B is true (or present), and both A and B are true (orpresent).

Also, use of “a” or “an” are employed to describe elements andcomponents of the invention. This is done merely for convenience and togive a general sense of the invention. This description should be readto include one or at least one and the singular also includes the pluralunless it is obvious that it is meant otherwise.

The term “hole transport” when referring to a layer, material, member,or structure, is intended to mean such layer, material, member, orstructure facilitates migration of positive charges through thethickness of such layer, material, member, or structure with relativeefficiency and small loss of charge.

The term “electron transport” means when referring to a layer, material,member or structure, such a layer, material, member or structure thatpromotes or facilitates migration of negative charges through such alayer, material, member or structure into another layer, material,member or structure.

The term “organic electronic device” is intended to mean a deviceincluding one or more semiconductor layers or materials. Organicelectronic devices include, but are not limited to: (1) devices thatconvert electrical energy into radiation (e.g., a light-emitting diode,light emitting diode display, diode laser, or lighting panel), (2)devices that detect signals through electronic processes (e.g.,photodetectors photoconductive cells, photoresistors, photoswitches,phototransistors, phototubes, infrared (“IR”) detectors, or biosensors),(3) devices that convert radiation into electrical energy (e.g., aphotovoltaic device or solar cell), and (4) devices that include one ormore electronic components that include one or more organicsemiconductor layers (e.g., a transistor or diode).

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. In the Formulae, the letters Q,R, T, W, X, Y, and Z are used to designate atoms or groups which aredefined within. All other letters are used to designate conventionalatomic symbols. Group numbers corresponding to columns within thePeriodic Table of the elements use the “New Notation” convention as seenin the CRC Handbook of Chemistry and Physics, 81^(st) Edition (2000).

Although methods and materials similar or equivalent to those describedherein can be used in the practice or testing of the present invention,suitable methods and materials are described below. All publications,patent applications, patents, and other references mentioned herein areincorporated by reference in their entirety. In case of conflict, thepresent specification, including definitions, will control. In addition,the materials, methods, and examples are illustrative only and notintended to be limiting.

It is to be appreciated that certain features of the invention whichare, for clarity, described above and below in the context of separateembodiments, may also be provided in combination in a single embodiment.Conversely, various features of the invention that are, for brevity,described in the context of a single embodiment, may also be providedseparately or in any subcombination. Further, reference to values statedin ranges include each and every value within that range.

The use of numerical values in the various ranges specified herein isstated as approximations as though the minimum and maximum values withinthe stated ranges were both being preceded by the word “about.” In thismanner slight variations above and below the stated ranges can be usedto achieve substantially the same results as values within the ranges.Also, the disclosure of these ranges is intended as a continuous rangeincluding every value between the minimum and maximum average valuesincluding fractional values that can result when some of components ofone value are mixed with those of different value. Moreover, whenbroader and narrower ranges are disclosed, it is within thecontemplation of this invention to match a minimum value from one rangewith a maximum value from another range and vice versa.

1-14. (canceled)
 15. An electronic device have at least one layercomprising a polymer composition comprising of: at least oneintrinsically conductive polymer having at least one monomer unitcomprising a pyridine-fused heteroaromatic, the at least one monomerunit selected from the group consisting of Formula I and Formula II:

wherein: R₁ through R₃ are independently selected so as to be the sameor different at each occurrence and are hydrogen or a substituent groupselected from the group consisting of alkyl, alkenyl, alkoxy, alkanoyl,alkylhio, aryloxy, alkylthioalkyl, alkylaryl, arylalkyl, amino,alkylamino, dialkylamino, aryl, alkylsulfinyl, alkoxyalkyl,alkylsulfonyl, arylthio, arylsulfinyl, alkoxycarbonyl, arylsulfonyl,acrylic acid, phosphoric acid, phosphonic acid, halogen, nitro, cyano,hydroxyl, epoxy, silane, siloxane, alcohol, benzyl, carboxylate, ether,ether carboxylate, amidosulfonate, ether sulfonate, ether sulfonic acid,ether sulfonimide, ester sulfonate, and urethane; or adjacent R groupstogether may form an alkylene or alkenylene chain completing a 3, 4, 5,6, or 7-membered aromatic or alicyclic ring, which ring may optionallyinclude one or more divalent nitrogen, sulfur, selenium, tellurium, oroxygen atoms, wherein any of the substituent groups may be fluorinated;Q is NR′, or S; and R′ is selected from the group consisting ofhydrogen, alkyl, alkenyl, aryl, alkanoyl, alkylthioalkyl, alkylaryl,arylalkyl, amino, epoxy, silane, siloxane, alcohol, benzyl, carboxylate,ether, ether carboxylate, ether sulfonate, ester sulfonate, andurethane; and at least one colloid-forming fluorinated acid polymer. 16.The device of claim 15, wherein the colloid-forming fluorinated acidpolymer has a fluorinated olefin backbone and a pendant group consistingof fluorinated ether sulfonate.